Slide 1: EXPLOSION WELDING
Definition of Explosion Welding : A solid-state welding process that produces coalescence by high velocity interaction of the work pieces produced by a controlled detonation. standoff
distance prime
component Base
component Detonator Explosive Component arrangement
for explosion welding Definition of Explosion Welding
Principles of Explosion Welding : Welding arrangement consists of three components -
Base component
Prime component
Explosive.
Base component remains stationary, supported by anvil. prime
component Base
component Explosive Component arrangement
for explosion welding Detonator Principles of Explosion Welding
Principles of Explosion Welding : Prime component is placed either parallel or at an angle to the base.
Explosive is distributed over top surface of prime component.
Upon detonation, prime component collides with base component to complete welding. Action between components
during explosion welding. Prime
component Jet Base
component Weld Principles of Explosion Welding
Slide 5: Linnert, Welding Metallurgy,
AWS, 1994
Process Variables and Controls : Variables
Collision Velocity
Collision Angle
Prime Component Velocity
These are Controlled By:
Component Mass
Explosive Charge
Initial Geometry - Standoff Distance or Angle Process Variables and Controls Explosive Pressure V = charge velocity
Explosives Used for Welding : Explosives Used for Welding High Velocity 14750-25000 ft/s
Trinitrotoluene (TNT)
Cyclotrimethylenetrinitramine (RDX)
Pentaerythritol tetranitrate (PETN)
Composition B
Composition C4
Primacord Low to Medium Velocity 4900-14750 ft/s
Ammonium nitrate
Ammonium nitrate sensitized with fuel oil
Ammonium perchlorate
Amatol
Amatol and sodatol diluted with rock salt to 30 to 35%
Dynamites
Nitroguanidine
Dilute PETN
Slide 8: Effect of Velocity on Explosion Weld Geometry Metals Handbook, ASM, 1983
Slide 9: In Parallel Arrangement
Standoff = 1/2 to 1.0 times clad Courtesy AWS handbook
Slide 10: In Angular Arrangement
Angle = 1 to 8 Degrees Metals Handbook, ASM, 1983
Slide 11: Wave Height Larger Standoff and Greater Angle Generally Leads
to Greater Wave Heights
Slide 13: Courtesy AWS handbook
Slide 14: Typical metal combinations that can be explosion welded Source AWS handbook
Applications of Explosion Welding : Any metal of sufficient strength and ductility can be joined.
Cladding flat plates constitutes the major commercial application.
Can be used to clad cylinders on inside or outside surface.
Transition joints can be made.
Tube to tube sheet joints in heat exchangers. Applications of Explosion Welding
Slide 16: Finished vessel fabricated from explosion
clad plate. Explosion welded 12 inch diameter
3003 aluminum to A106 grade B
steel tubular transition joint. Courtesy AWS handbook
Slide 17: Plug Welding of a Tube within a Pressure Vessel Tube Sheet Courtesy AWS handbook
Slide 18: Courtesy AWS handbook Using Explosion to seal mechanical plug
Slide 19: Metals Handbook, ASM, 1983
Slide 20: Courtesy AWS handbook Explosive Pipe Welding
Slide 21: Thin Steel
Thick Aluminum Explosion Welded Cut Strip/width of shoe Insert Nail Groove & Hole Form Shoe Backman, C “Method and a Blank for the Production of Horseshoes”, Patent 5,727,376 Mar 17, 1998 Explosion Bonding of Horseshoes Steel Aluminum
Slide 22: Projectile Welding of Aluminum Joseph, A., “Projectile Welding”, US Patent 5,474,226 Dec 12, 1995 Multi-Molecular Nucleation surface between projectile of same material and sheets
Slide 23: Questions
Slide 24: Homework Explosive Weld
Slide 25: PROCESS SELECTION
Process Selection : Process Selection Selection of solid state welding processes
depends on the following factors:
Performance of the welding processes under existing conditions
Advantages of the processes involved
Durability of the welds produced
Materials to be welded
Economic viability of the process
Advantages of Solid State Welding : Advantages of Solid State Welding Eliminates liquid phases
Makes the joining of many dissimilar metal combinations possible
Can be performed with little or no deformation in some cases
Can be performed at very low temperatures in some cases
Some solid state processes can weld large areas in a single welding operation
Some processes are relatively rapid
Advantages of Solid State Welding : Eliminates liquid phases
Example: cold welding, friction welding, ultrasonic welding, diffusion welding and explosion welding Advantages of Solid State Welding
Advantages of Solid State Welding : Makes the joining of many dissimilar metal combinations possible
Example: friction welding, explosion welding, diffusion welding. Advantages of Solid State Welding
Advantages of Solid State Welding : Can be performed with little or no deformation in some cases
Example: diffusion welding Advantages of Solid State Welding
Advantages of Solid State Welding : Some solid state processes can weld large areas in a single welding operation
Examples: diffusion welding and explosion welding Advantages of Solid State Welding
Advantages of Solid State Welding : Some solid state welding processes are relatively rapid
Example: ultrasonic welding, cold welding and friction welding Advantages of Solid State Welding
Slide 33: Homework Search Patent Literature